poVoq luceos clearing the cache still gives the same error Restarting it is a bit complicated as this is a Plesk host, but I guess switching php versions does something similar or so?
luceos poVoq never switch php versions, composer update commands identify your php version and install compliant php packages. Restarting apache/fpm will clear the opcache if it is enabled.
poVoq Well... I definitely installed everything via composer with php8, but now it only works with php7.4...
luceos We just released Flarum v1.0.3 to solve this issue, see: https://discuss.flarum.org/d/27395-dev-diary-build-18/37 Make sure to follow the instructions carefully in case you used composer commands to downgrade the illuminate packages.
luceos shebaoting "illuminate/filesystem": "", "illuminate/support": "8.47.", "kylekatarnls/laravel-carbon-2": "", "nesbot/carbon": "", You should probably remove these lines from your composer.json. The carbon dependencies don't make a difference.